Bringing up compression

Du Farmsabit · Mar 1, 2015

8N motor power plant for a combine, it hasn't run for a lot of years. Rebuilt mag, carb, new plugs, good wires, runs on either. I put some diesel down the plug holes to clean it, then put 10/30 after a few days. Brought compression up to 70,70,70,100. Still not sucking gas up into the engine. Royce said to use ATF, so i did that today, took the carb off, pugs out, put in maybe quarter cup of ATF in holes, and cycled motor a couple times.... My question,,, now what? Do i wait a couple days, let it soak, do i do this a few times, then maybe put oil back on top again? I am hoping i don't have to do a rebuild, but i will if i must. Thanks in advance.

HCooke · Mar 1, 2015

?Do i wait a couple days, let it soak, do i do this a few times, then maybe put oil back on top again?

I would wait a week or so and maybe the ATF will unstick the rings. More ATF in a few days won't hurt. If it starts, let it warm up a bit and then change the oil.

Du Farmsabit · Mar 1, 2015

Ok, thanks, maybe add some more in a couple days, cycle, wait a couple more days. Will i have to add oil to check compression, or can i do a test with just the ATF in it? I'm barely a mechanic, thanks.

old · Mar 1, 2015

I have been using ATF for decades and probably the first person to say any thing about it on the forums. FILL the cylinders with ATF and then put the plugs back in to keep dirt etc out of the engine. Let it sit at least a week. Then if you can turn it over by hand with the plugs in. It should hydro lock on you when you do but that will push the ATF down into the rings better. Next pull the plugs and spin it over to clear the ATF which by the way will make a mess. Next put a little gas in each cylinder say a 1/4 teaspoon and try to fire it up

Dell (WA) · Mar 1, 2015

Du........pay attention.......compression is ALWAYS stated in "dry" specs. Ford 9N/2N/8N is 90psi MIN. A new rebuilt engine will test out about 125psi. The use of "oil" is to gauge the "wear" of the rings and resultant loss of compression. Good engine compression, oil will up about 10psi, a worn engine will up about 20psi ...or... more. Understand the difference??? Oh BTW, yer BelchFire-V8 will test about 165psi. Diesel's will test about 225psi. ........HTH, Dell

Royse · Mar 1, 2015

What the guys are telling you about waiting is right.
A week or more, adding some as you go.
It needs time to eat the rust loose if it can get that job done at all.
After all, that rust didn't form over night. It's not going away overnight.

I would NOT put raw gas in the cylinders and try to hand crank
that engine. Maybe I'm a chicken, but it sounds like a recipe for
a broken thumb/hand/wrist to me.

Du Farmsabit · Mar 1, 2015

Thanks for that Dell, Appreciate it.

Du Farmsabit · Mar 1, 2015

Thanks old, i can only put so much ATF if before it starts running out the manifold. I took out the carb to keep it out of there for now. I turned it over a couple times, put more in, then put the plugs back in. I will wait for a week. Thanks. What is "hydro lock"?

Du Farmsabit · Mar 1, 2015

Hi Royce, you guys are such a huge help. Thanks.
OK, i'll wait,,, tick - tock,, not the easiest
thing to do, lol. I haven't tried the gas method,
but the starting fluid works good. Today i went
out, and squirted a little in, and she fired right
up, i kept feeding it for about a minute before it
coughed and died. That's when i decided to try
your suggestion, i figure this is going to have to
work, or, i'm gonna need to do a tear down. The
new carb. seems to be fine, i took it off and
inspected it some. In the mean time, i ordered a
new thermostat, and am watching vids on rebuilding
the motor just in case. I loved your post on your
new project, made me realize that i can actually
do things i thought i couldn't.... this place is a
huge inspiration for me, i can't tell you how much
that means. Thanks again.

Royse · Mar 1, 2015

"made me realize that i can actually do things i thought i couldn't"

Yes, you can! And there are many knowledgeable, helpful folks
on this site that will help you get it done! They helped me along
as I learned Fords and they're still here helping others.

I understand the problem trying to wait, but the alternative is
MUCH more expensive!

Here's an example of what patience and ATF can do. YT Post
Your mileage may vary, but this one worked out well.

Du Farmsabit · Mar 1, 2015

haha,,, nice! thanks! nice field too! I've only
got 10 acres which is why i am so interested in a
small combine. My working tractor is a JD2640, so
far i've gotten a 3 bottom, and old case drill, a
40ft harrow cart, and a JD210 disc. I came out
here from the city just 13 years ago, didn't know
the difference between a heifer and a Hereford.
lol Been through the mill, divorce etc... now it's
just me, wondering what to do with this place, too
small to justify equipment, to big for a lawn
mower. At 4k/acre it's pretty tough to get
anything of any size round here.

dbNga · Mar 1, 2015

Hydro lock happens when you have a fluid in a cylinder and when it gets compressed with no relief, something is going to bend, break or burst. This is a threat when the fuel valve is not shut off when fuel tank is above engine/carb as is on 8ns, xoo & x01 Fords. That is one reason why you want to be sure and spin eng without plugs after you soak with atf.

Tall T · Mar 2, 2015

Pick up a spray can of Amsoil MP and spray flood your walls a few times over a couple of days -- empty the can. It is an incredible de-rusting penetrant and nice and thin so you won't need to worry about hydrolock. You need a light oil that also cuts rust and corrosion. Try it on some other rusty things you have and you'll quickly be sold on it.

I know how popular the ATF is but it does not dissolve rust.
Maybe chase the MP with some ATF if you want a heavier oil on the walls to start.

Here's my steering column after spraying, waiting an hour while i rigged up a puller. What you see is like rust pudding thanks to the Amsoil MP and those rusty lumps are actually loose and sliding down the splines. I've been using it for 40 years and nothing I know beats it. Unlike all others, it never oxidizes after the fact and turns to gum in 6 months like WD.

If you saw me spray this post just after what you see here, you would actually see it wash all this away to clean steel for the most part but it wastes fluid that way, so I'll use a wire brush and rags to save on the juice.

Looks like a coil or two is broken off my spring. Anyone got a loose one?

Du Farmsabit · Mar 2, 2015

Wow, thanks! *takes note* I'll try that if the ATF
doesn't work, but that looks like handy stuff to
have around anyway. As i work on this machine, i'm
going to have a bunch of that brown lock tight to
deal with.

Du Farmsabit · Mar 2, 2015

Ah, thanks,,, sure hope this works,, but won't know for a week

old · Mar 2, 2015

Hydro lock is when you have both valves closed and you turn it over on compression the engine should lock up unless the valves are not sealing as they should.

Ken(Ark) · Mar 2, 2015

Thanks. What is "hydro lock"?

Here is a good article with pics

http://en.wikipedia.org/wiki/Hydrolock

RevJJ · Mar 2, 2015

I saw your video on youtube. I noted that it was trying to run on ether. You have gravity feed to your carburetor since your tank is over the engine...if your system is really tight, the gas will not flow to the carb. Bleed the line to the carb by breaking the line at the fitting (ie loosening the fitting until fuel runs). Then, if there is a drain on the carb open it until fuel runs out. your issue isn't compression. if you have a 100 lbs the engine should run. you just haven't gotten fuel to your carb. and it isn't unheard of for needle valves to stick in new carbs

Du Farmsabit · Mar 3, 2015

Ok, thanks, i've done that before, but i will do that again, just in case, thanks for the reminder

The carb, was full of gas when i removed it, before i put the ATF in.

Du Farmsabit · Mar 3, 2015

I went out yesterday, and put a little more ATF in, put the plugs back in, and it did lock up, i loosened the plugs, and turned it a couple times, and now i'm just going to wait a few days.

Du Farmsabit · Mar 3, 2015

Thanks! Yikes!

Bringing up compression

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